Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Dairy Sci ; 103(11): 10048-10059, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32952027

RESUMO

Whey proteins are a primary component of milk replacers (MR) and are considered the gold standard for calves. Alternative protein sources may decrease MR cost if calf performance is similar. A blend of bovine plasma protein and modified wheat protein might be a good partial replacement for whey protein. Usually MR is fed twice daily, but feeding 3 times daily might increase efficiency of nutrient use, especially with MR containing alternate proteins. Therefore, our objective was to determine the effects of 2 MR, containing either entirely whey protein (CON) or a combination of whey protein, bovine plasma protein, and modified wheat protein (WBP), when fed in either 2 or 3 meals daily on calf growth and health. Female and male Holstein calves (n = 103) housed in individual hutches were studied for the first 63 d of life, with additional measurements obtained at wk 12 of life in group housing. The MR contained 25% CP, 17% fat, and a Lys:Met ratio of 3.1:1. Individual treatments arose from the 2 × 2 factorial arrangement of MR formulation and frequency of feeding. After colostrum, calves were fed MR (12.5% solids) at daily rates of dry matter dependent on age. Amounts were as follows: d 3 to 10 = 0.52 kg/d (2× = 0.259 kg, 3× = 0.173 kg per feeding); d 11 to 20 = 0.68 kg/d (2× = 0.341 kg, 3× = 0.227 kg per feeding); d 21 to 42 = 0.84 kg/d (2× = 0.42 kg, 3× = 0.28 kg per feeding); d 43 to 46, 47, 49, and 51 = 0.42 kg/d, with both 2× and 3× changed to 1 feeding daily and skip days (d 48 and 50) between where calves were not given MR; and d 52 = calves weaned. Starter was fed and intake was measured from d 1 until d 63. Intakes, health scores, attitude scores, and fecal scores were measured daily. Body weight (BW) and growth measurements were obtained weekly until wk 8 and again at wk 12. Blood samples were obtained at 0, 24, and 48 h and then on d 5, 14, 28, and 42 of age. Starter intake was greater for calves fed WBP versus CON during wk 7 to 9. Final BW and hip width at wk 12 were greater for calves fed WBP than for calves fed CON. Calves fed 2× had greater mean and final BW to wk 6 and greater feed efficiency (gain:feed ratio) than calves fed 3×. Blood variables supported the generally similar growth outcomes. Health outcomes did not differ between diets or feeding frequencies. Overall, calves fed WBP had increased starter intake and greater BW gains during wk 7 to 12 than calves fed CON, and calves fed 2× had increased growth and feed efficiency compared with those fed 3×.


Assuntos
Bovinos/fisiologia , Comportamento Alimentar , Substitutos do Leite/metabolismo , Animais , Peso Corporal , Dieta/veterinária , Feminino , Masculino , Nutrientes/metabolismo , Gravidez , Proteínas/metabolismo , Desmame
2.
Sci Rep ; 10(1): 4347, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32132559

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

3.
Plant Dis ; 103(4): 721-728, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30777802

RESUMO

Panama disease caused by Fusarium oxysporum f. sp. cubense has devastated banana production worldwide. This work aimed to determine effective disinfectants against two races of F. oxysporum f. sp. cubense, race 1 and tropical race 4 (TR4), for implementation with on-farm biosecurity procedures against this disease following the outbreak of TR4 in North Queensland in 2015. A total of 32 commercial disinfectants were screened and their activity was assessed after ≤30 s, 5 min, 30 min, and 24 h of contact with an F. oxysporum f. sp. cubense suspension containing 105 chlamydospores/ml without and with soil added (0.05 g/ml). Of the disinfectants tested, the quaternary ammonium compounds containing ≥10% active ingredient were found to be the most effective against both F. oxysporum f. sp. cubense races. These products, when used at a 1:100 dilution, completely inhibited the survival of all F. oxysporum f. sp. cubense propagules across all the contact times regardless of the absence or presence of soil. The bioflavonoid product EvoTech 213 and bleach (10% sodium hypochlorite) used at a 1:10 dilution also eliminated all F. oxysporum f. sp. cubense propagules across all the contact times. None of the detergent-based or miscellaneous products tested were completely effective against both F. oxysporum f. sp. cubense races even used at a 1:10 dilution. Soil decreases the efficacy of disinfectants and therefore must be removed from contaminated items before treatments are applied.


Assuntos
Desinfetantes , Microbiologia de Alimentos , Fusarium , Desinfetantes/farmacologia , Desinfetantes/normas , Microbiologia de Alimentos/métodos , Fusarium/efeitos dos fármacos , Musa/microbiologia , Doenças das Plantas/prevenção & controle , Queensland
4.
Sci Rep ; 8(1): 11218, 2018 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-30046045

RESUMO

There is growing evidence for bacteria playing a role in the pathogenesis and formation of pigmented gallstones from humans. These studies mainly involved cultivation of gallstone-associated bacteria and 16S rRNA profiling, providing an indirect link between processes involved in gallstone formation by the bacteria in-situ. Here, we provide functional metagenomic evidence of a range of genes involved in bile stress response, biofilm formation, and anaerobic energy metabolism by Gram-negative Klebsiella in pigmented gallstones from a 76-year-old male patient. Klebsiella was also present in one cholesterol-type stone in a 30-year-old female patient who had additional cholesterol gallstones characterised by Gram-positive bacteria. Pigmented stones further revealed a predominance of genes involved in carbohydrate metabolism, whilst cholesterol stones indicated a profile dominanted by protein metabolism possibly reflecting known chemical differences between Gram-negative and Gram-positive biofilm matrices. Archaeal genes were not detected. Complementary carbon and hydrogen isotopic analyses of cholesterol within the patients' stones revealed homogeneity, suggesting a common diet or cholesterol biosynthesis pathway that has little influence on microbial composition. This pilot study provides a framework to study microbial processes that play a potential role in gallstone formation across markedly different types of stones and patient backgrounds.


Assuntos
Bactérias/genética , Colesterol/genética , Cálculos Biliares/microbiologia , Metagenômica , Adulto , Idoso , Bactérias/classificação , Bactérias/isolamento & purificação , Biofilmes/crescimento & desenvolvimento , Feminino , Cálculos Biliares/genética , Cálculos Biliares/patologia , Humanos , Klebsiella/genética , Klebsiella/patogenicidade , Masculino , Pigmentação/genética , RNA Ribossômico 16S/genética
5.
Geobiology ; 15(1): 184-194, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27686333

RESUMO

Over 8600 species are currently recorded in the phylum Porifera (sponges). They produce a large diversity of biochemical compounds including sterols, with more than 250 different sterols identified. Some of these sterols are of great interest, due to their use for fingerprinting in ecological and biomarker (molecular fossil) studies. As a large number of identified extant species from biodiversity surveys are housed in museum collections, preserved in ethanol, these present a potentially rich source of identified specimens for comparative lipid analyses. Here, we show that, in at least one species, sterol distributions obtained from the ethanol used to preserve specimens of sponges were representative, and comparable to the sterol distribution obtained from wet-frozen and from freeze-dried tissue from the same species. We employed both GC-MS and two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS), with an improved signal-to-noise ratio for even minor constituents. Analysis of two additional specimens of the same species, but of different provenance, resulted in detection of marked differences in sterol composition, which could be attributed to variations in geography, environmental conditions, microbial communities, diet or cryptic speciation. The possibility of using ethanol from identified, preserved museum sponges could drastically increase the number of available samples. This could enable the study of their sterol complements, and the detailed investigation of differences due to geographical and oceanographic, phylogenetic, and other factors in unprecedented detail.


Assuntos
Fósseis , Poríferos/química , Esteróis/análise , Animais , Espectrometria de Massas , Museus
6.
Geobiology ; 12(5): 469-87, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25039712

RESUMO

The present study investigated the influence of abiotic conditions on microbial mat communities from Shark Bay, a World Heritage area well known for a diverse range of extant mats presenting structural similarities with ancient stromatolites. The distributions and stable carbon isotopic values of lipid biomarkers [aliphatic hydrocarbons and polar lipid fatty acids (PLFAs)] and bulk carbon and nitrogen isotope values of biomass were analysed in four different types of mats along a tidal flat gradient to characterize the microbial communities and systematically investigate the relationship of the above parameters with water depth. Cyanobacteria were dominant in all mats, as demonstrated by the presence of diagnostic hydrocarbons (e.g. n-C17 and n-C17:1). Several subtle but important differences in lipid composition across the littoral gradient were, however, evident. For instance, the shallower mats contained a higher diatom contribution, concordant with previous mat studies from other locations (e.g. Antarctica). Conversely, the organic matter (OM) of the deeper mats showed evidence for a higher seagrass contribution [high C/N, 13C-depleted long-chain n-alkanes]. The morphological structure of the mats may have influenced CO2 diffusion leading to more 13C-enriched lipids in the shallow mats. Alternatively, changes in CO2 fixation pathways, such as increase in the acetyl COA-pathway by sulphate-reducing bacteria, could have also caused the observed shifts in δ13C values of the mats. In addition, three smooth mats from different Shark Bay sites were analysed to investigate potential functional relationship of the microbial communities with differing salinity levels. The C25:1 HBI was identified in the high salinity mat only and a lower abundance of PLFAs associated with diatoms was observed in the less saline mats, suggesting a higher abundance of diatoms at the most saline site. Furthermore, it appeared that the most and least saline mats were dominated by autotrophic biomass using different CO2 fixation pathways.


Assuntos
Cianobactérias/metabolismo , Diatomáceas/metabolismo , Sedimentos Geológicos/microbiologia , Lipídeos/análise , Biomarcadores/análise , Salinidade , Austrália Ocidental
7.
Persoonia ; 29: 146-201, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23606771

RESUMO

Novel species of microfungi described in the present study include the following from Australia: Catenulostroma corymbiae from Corymbia, Devriesia stirlingiae from Stirlingia, Penidiella carpentariae from Carpentaria, Phaeococcomyces eucalypti from Eucalyptus, Phialophora livistonae from Livistona, Phyllosticta aristolochiicola from Aristolochia, Clitopilus austroprunulus on sclerophyll forest litter of Eucalyptus regnans and Toxicocladosporium posoqueriae from Posoqueria. Several species are also described from South Africa, namely: Ceramothyrium podocarpi from Podocarpus, Cercospora chrysanthemoides from Chrysanthemoides, Devriesia shakazului from Aloe, Penidiella drakensbergensis from Protea, Strelitziana cliviae from Clivia and Zasmidium syzygii from Syzygium. Other species include Bipolaris microstegii from Microstegium and Synchaetomella acerina from Acer (USA), Brunneiapiospora austropalmicola from Rhopalostylis (New Zealand), Calonectria pentaseptata from Eucalyptus and Macadamia (Vietnam), Ceramothyrium melastoma from Melastoma (Indonesia), Collembolispora aristata from stream foam (Czech Republic), Devriesia imbrexigena from glazed decorative tiles (Portugal), Microcyclospora rhoicola from Rhus (Canada), Seiridium phylicae from Phylica (Tristan de Cunha, Inaccessible Island), Passalora lobeliae-fistulosis from Lobelia (Brazil) and Zymoseptoria verkleyi from Poa (The Netherlands). Valsalnicola represents a new ascomycete genus from Alnus (Austria) and Parapenidiella a new hyphomycete genus from Eucalyptus (Australia). Morphological and culture characteristics along with ITS DNA barcodes are also provided.

8.
Hum Mol Genet ; 12(11): 1241-52, 2003 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-12761039

RESUMO

Germline mutations of the fumarate hydratase (FH, fumarase) gene are found in the recessive FH deficiency syndrome and in dominantly inherited susceptibility to multiple cutaneous and uterine leiomyomatosis (MCUL). We have previously reported a number of germline FH mutations from MCUL patients. In this study, we report additional FH mutations in MCUL and FH deficiency patients. Mutations can readily be found in about 75% of MCUL cases and most cases of FH deficiency. Some of the more common FH mutations are probably derived from founding individuals. Protein-truncating FH mutations are functionally null alleles. Disease-associated missense FH changes map to highly conserved residues, mostly in or around the enzyme's active site or activation site; we predict that these mutations severely compromise enzyme function. The mutation spectra in FH deficiency and MCUL are similar, although in the latter mutations tend to occur earlier in the gene and, perhaps, are more likely to result in a truncated or absent protein. We have found that not all mutation-carrier parents of FH deficiency children have a strong predisposition to leiomyomata. We have confirmed that renal carcinoma is sometimes part of MCUL, as part of the variant hereditary leiomyomatosis and renal cancer (HLRCC) syndrome, and have shown that these cancers may have either type II papillary or collecting duct morphology. We have found no association between the type or site of FH mutation and any aspect of the MCUL phenotype. Biochemical assay for reduced FH functional activity in the germline of MCUL patients can indicate carriers of FH mutations with high sensitivity and specificity, and can detect reduced FH activity in some patients without detectable FH mutations. We conclude that MCUL is probably a genetically homogeneous tumour predisposition syndrome, primarily resulting from absent or severely reduced fumarase activity, with currently unknown functional consequences for the smooth muscle or kidney cell.


Assuntos
Fumarato Hidratase/genética , Neoplasias Renais/genética , Leiomiomatose/genética , Mutação , Neoplasias Cutâneas/genética , Neoplasias Uterinas/genética , Erros Inatos do Metabolismo dos Aminoácidos/genética , Sequência de Aminoácidos , Estabilidade Enzimática , Feminino , Fumarato Hidratase/química , Fumarato Hidratase/deficiência , Fumarato Hidratase/metabolismo , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Neoplasias Renais/secundário , Leiomiomatose/patologia , Dados de Sequência Molecular , Conformação Proteica , Estabilidade de RNA , RNA Mensageiro/metabolismo , Homologia de Sequência de Aminoácidos , Neoplasias Cutâneas/patologia , Neoplasias Uterinas/patologia
9.
Vision Res ; 40(8): 1019-26, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10720671

RESUMO

While it is now established that astigmatism is more prevalent in infants and young children than in the adult population, little is known about the functional significance of this astigmatism, especially its role, if any, in emmetropization and the development of myopia. Manifest refractions (mean of 16 per subject) were obtained from 245 subjects starting in the first year, with 6-23 years of regular follow-up. Results showed that infantile astigmatism is associated with increased astigmatism and myopia during the school years. Two possible mechanisms underlying this association are discussed: (1) infantile astigmatism disrupts focusing mechanisms; and (2) ocular growth induces astigmatism and myopia.


Assuntos
Astigmatismo/complicações , Miopia/etiologia , Adolescente , Envelhecimento/fisiologia , Criança , Pré-Escolar , Olho/crescimento & desenvolvimento , Feminino , Seguimentos , Humanos , Lactente , Masculino , Refração Ocular/fisiologia
10.
Optom Vis Sci ; 76(6): 363-9, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10416930

RESUMO

The literature on myopigenesis suggests an active emmetropization mechanism regulated by optical defocus. The strongest evidence comes from compensatory ocular growth in response to lens-induced defocus in different species of animals. Based on these results, it has been suggested that, however useful, spectacle intervention for the optical correction of human myopia would lead to its exacerbation. The present study seeks to evaluate the progression of juvenile-onset myopia in children differentiated by their lens wear patterns. Data from 43 myopes from our longitudinal study of refraction were evaluated, with myopia defined as a spherical equivalent of at least -0.50 D. Refractions were obtained in the laboratory by noncycloplegic retinoscopy performed by one experienced optometrist at regular intervals. Information regarding the subjects' prescription lens-wearing history was obtained from the subjects and their eye care providers. Based on their wearing patterns, subjects were divided into four categories: (1) full-time wearers; (2) myopes who switched from distance to full-time wear; (3) distance wearers; and (4) nonwearers. Exponential functions were fit to the individual refraction data. The age of onset of myopia, the mean myopia at onset of spectacle wear, and the refractive shift over a period of at least 3 years were derived from these fits. Results show that the 3-year refractive shifts are not significantly different among the four groups. A comparison of the extreme conditions, i.e., full-time vs. nonwear categories, also revealed no significant difference when the data were corrected for age effects despite the fact that the nonwearers exhibited an age-adjusted 3-year progression approximately one-half that of the full-time wearers. In summary, the present study failed to demonstrate any overall effects of spectacle intervention on the progression of human myopia. Further investigation using a larger sample is warranted.


Assuntos
Óculos , Miopia/prevenção & controle , Idade de Início , Criança , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Miopia/epidemiologia , Miopia/fisiopatologia , Prevalência , Refração Ocular , Resultado do Tratamento
11.
Optom Vis Sci ; 76(6): 381-6, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10416932

RESUMO

In an attempt to determine the role of genetic factors in the development of myopia, we examined the relationship of infantile refractive error and parental history to juvenile-onset myopia and analyzed 43 pedigrees affected by juvenile-onset myopia. Refraction data collected at regular intervals from a sample of juvenile subjects participating in a 24-year longitudinal study of refractive error were used. Results showed that children with two myopic parents were 6.42 times as likely to become myopic as children with one or no myopic parents. Furthermore, children who had refractions in the lower half of the distribution at 6 to 12 months of age were 4.33 times as likely to develop myopia as children who had refractions in the upper half of the distribution at 6 to 12 months of age. The pedigree analysis indicated that 63% of individuals considered at risk for developing juvenile-onset myopia actually became myopic, with an equal number of affected males and females. These results suggest that juvenile-onset myopia of moderate amounts may be inherited as a complex trait involving both genetic and environmental factors.


Assuntos
Miopia/genética , Refração Ocular , Adolescente , Adulto , Distribuição por Idade , Idade de Início , Criança , Pré-Escolar , Progressão da Doença , Feminino , Predisposição Genética para Doença , Humanos , Lactente , Masculino , Miopia/epidemiologia , Miopia/fisiopatologia , Razão de Chances , Linhagem , Prevalência , Inquéritos e Questionários
12.
Ophthalmic Physiol Opt ; 19(2): 173-9, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10615453

RESUMO

In children little is known about the relationship between the AC/A ratio and the development of myopia, although they have been linked in adults. The purpose of this study was to investigate the interaction between accommodation and convergence and its relationship to refractive errors in children. Accommodation was measured for the right eye using the Canon R-1 autorefractor, and concomitant changes in vergence were assessed using a Maddox rod and a Risley prism before the left eye. Thirty-three myopic and 68 emmetropic children were tested wearing best subjective correction while looking at a distant (4.0 m) letter array and a near (0.33 m) one through additional plus and minus lenses. Lens-induced and distance-induced response AC/A ratios were calculated from the data. Both types of AC/A ratios are elevated in myopic children, who show reduced accommodation and enhanced accommodative convergence. Myopic children with esophoria underaccommodate at near. This suggests that a child who is esophoric must relax accommodation to reduce accommodative convergence and maintain single binocular vision. The reduction in accommodation could produce blur during near work, which could induce myopia as in animal models.


Assuntos
Acomodação Ocular , Convergência Ocular , Miopia/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , Óculos , Humanos , Miopia/terapia , Optometria/instrumentação , Optometria/métodos , Erros de Refração/fisiopatologia
13.
Clin Exp Dermatol ; 17(1): 53-5, 1992 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1424263

RESUMO

A patient with systemic lupus erythematosus who presented with subcutaneous nodules over the flexor aspect of the fingers in association with arthritis and Raynaud's phenomenon is described. Histopathological examination of the nodules showed appearances consistent with rheumatoid nodules. Further investigations revealed leucopenia and circulating anti-nuclear antibody but negative rheumatoid factor. Immunofluorescence studies of normal non-light exposed skin showed the presence of IgM deposits at the dermo-epidermal junction consistent with systemic lupus erythematosus. The nodules almost disappeared following treatment with hydroxychloroquine. Rheumatoid-like nodules have been reported in systemic lupus erythematosus, although rarely. However, the distribution of the nodules and the patient's clinical course differ from the few cases previously reported in the literature.


Assuntos
Lúpus Eritematoso Sistêmico/complicações , Nódulo Reumatoide/complicações , Adulto , Feminino , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Nódulo Reumatoide/diagnóstico
14.
J Am Acad Dermatol ; 22(2 Pt 2): 334-7, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2303588

RESUMO

Extramedullary hematopoiesis was found in the cutaneous papulonodular eruption of a 72-year-old man with myelofibrosis. This is the first reported case to show a preponderance of atypical megakaryocytes in skin lesions. The patient was also unusual in that he had marked generalized lymphadenopathy. The skin lesions almost disappeared after treatment with hydroxyurea.


Assuntos
Hematopoese Extramedular , Mielofibrose Primária/fisiopatologia , Idoso , Biópsia , Hematopoese Extramedular/efeitos dos fármacos , Humanos , Hidroxiureia/uso terapêutico , Masculino , Megacariócitos/patologia , Pele/fisiopatologia
16.
Practitioner ; 232(1454 ( Pt 1)): 953-6, 1988 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-3076945
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...